This is only tangentially related to the article, but maybe someone can explain this YC alum trend to me. Why is it that the home link (and in many cases the lo

This is only tangentially related to the article, but maybe someone can explain this YC alum trend to me. Why is it that the home link (and in many cases the logo as well) of blog.company.com link to the base blog.company.com. I would assume the primary purpose of a company blog, technical or otherwise is to drive traffic to your main site. Without a clear link, i feel this is ill served. What am i missing?